气象2017，Vol.43Issue(11)：1339-1353,15.DOI:10.7519/j.issn.1000-0526.2017.11.003
2014年两次相似路径影响云南台风降水差异成因分析
Cause Analysis of Precipitation Difference Between Two Typhoons Influencing Yunnan Along Similar Tracks in 2014
摘要
Abstract
Typhoons Ramasun and Kalmaegi along west route influenced Yunnan in 2014,where rainstorm distribution characteristics and the relative position of tropical cyclone had significant differences.The diagnosis results indicate that production of rainstorm distribution difference was mainly caused by the role of ambient flow field,which caused frontogenesis,then energy change,together with the effect of topography.Particularly,low-level westerly (easterly) jet and convergence at south (north) side of Ramasun Typhoon center enhanced,causing generation of heavy rainfall.However,because water vapor content in lower layer of south side was higher than that of north side,the southwest Yunnan edge and Red River Valley windward slope had uplift effect,the rainfall amplified.Precipitation of south side was heavier than that of north side.In addition,thermodynamic properties differences of flow between south and north side caused frontogenesis.Frontal zone at low-level enhanced,beneficial to the development of severe precipitation on the northeastern side of Ramasun,southeast Yunnan.Furthermore,intersection of the easterly and westerly made divergence enhancing,then baroclinic available potential energy was released,which caused divergent wind kinetic energy to increase,and increase of divergent wind kinetic energy was relative to the change of precipitation peak caused by Ramasun.However,as Kalmaegi was influencing Yunnan,the center position of tropical cyclone and Bay of Bengal low pressure were both further south,and the southwest monsoon was also further south.The low-level jet at Kalmaegi northeastern side was the main factor influencing rainfall over Yunnan,and the intensity of low-level jet and zonal convergence at the jet front left quadrant were both stronger than that by Ramasun,so the precipitation of Kalmaegi northeastern side was more intense than that of Ramasun.In addition,the uplift effect of terrain played an important role in the generation of heavy rainstorm at south Yunnan edge.Moreover,frontal zone at low-level enhanced,which was also beneficial to the development of severe precipitation over northeast Yunnan at the northeastern side of Kalmaegi.Furthermore,increasing rotational wind kinetic energy was relative to precipitation peak,and the formation of the first precipitation peak in the edom of central Yunnan was related to baroclinic processes.However,at the second precipitation peak,south jet was strengthened on the east side of depression inverted trough,and rotational velocity field transported kinetic energy to heavy rain area,then kinetic energy over heavy rain area increased significantly,which was related to barotropic processes.关键词
相似路径台风/降水差异/低空急流/锋区作用/辐散风动能/地形作用Key words
typhoon with similar tracks/precipitation difference/low-level jet/frontal zone effect/divergent wind kinetic energy/topographic effect分类
天文与地球科学引用本文复制引用
梁红丽,程正泉..2014年两次相似路径影响云南台风降水差异成因分析[J].气象,2017,43(11):1339-1353,15.基金项目
国家自然科学基金项目(41365007和41365006)共同资助 （41365007和41365006）
